In the animal world, the male is usually the fancy dresser. But in the masculine jungle of global politics, it is the first lady who has to seduce a fickle public on behalf of her dully plumaged partner.

Peng Liyuan, the glamorous wife of Xi Jinping, China’s new president, triumphed on her first foreign outing this week. Like many modern first ladies (think particularly Michelle Obama and Carla Bruni Sarkozy) Ms Peng, a popular Chinese singer, is a career woman. Also like her peers, she has adopted the practice of taking to the official catwalk dressed entirely in homegrown designer labels. This does more to advertise Chinese couture than any fashion show. But why should only the wives of the world’s leaders be held to such high fashion standards? If anything, the men are more in need of flair than today’s first ladies.

David Cameron’s sartorial style can only be defined as bland. Fran?ois Hollande lacks the Gallic chic that should have been his birthright. And Vladimir Putin’s dress sense could be summed up as Rambo with a dash of Tarzan – but only at his dacha. At global summits he blends in perfectly with the sea of dull, dark suits.